Unmanned aerial vehicle (UAV or drone) technology continues to improve rapidly. Drones are able to perform a variety of missions with greater operational flexibility and at a lower cost than comparable manned aircraft. A wide spectrum of users, including industry, private citizens, and governments, are using or are expected to use these systems, which may play a transformative role in fields as diverse as urban infrastructure management, farming, transportation, public safety, coastal security, military training, search and rescue, and disaster response.
However, introducing drones into airspace is challenging to the aviation community. One of the challenges is to make sure that drones do not run into obstacles, airplanes, helicopters, or each other. There are also substantial concerns on drones flying over private, commercial, or restricted areas without knowledge of various restrictions and regulations in different areas or without permissions.